Thai Prime Minister Abhisit Vejjajiva declared a state of emergency in Bangkok on Wednesday, handing the army broad powers to restore order after weeks of disruptive street protests by anti-government demonstrators.
The announcement came after protesters broke into Parliament and senior government officials had to be evacuated by helicopter. Some lawmakers scaled the compound's walls to escape.
The government already had placed Bangkok under the strict Internal Security Act.
But a state of emergency includes more sweeping powers. It gives the military authority to restore order and allows authorities to suspend certain civil liberties and ban all public gatherings of more than five people.
The so-called Red Shirt protesters are demanding that Abhisit dissolve Parliament within 15 days and call new elections. He has offered to do so by the end of the year.
They have been camped in Bangkok since March 12 and have ignored all other decrees for them to stop their protests.
Abhisit has become the target of harsh criticism for failing to take strong measures to end the protests. He has tried negotiations, and has had security forces pull back from possible confrontations.
In a statement broadcast on all television stations Tuesday, he explained that "the current fragile situation demands careful maneuvering."
"We need to plan and implement everything to the last detail and with thorough care. The last thing we want is for the situation to spiral out of control."